Electrical insulators, or dielectrics, are utilized in a variety of items to separate electrical conductors. Insulators can be dry type or fluid-filled. Fluid filled insulators insulate conductors by using a fluid such as oil. Fluid filled insulators are best suited for high heat applications, such as large industrial complexes. However, fluid filled insulators are costly to manufacture and costly to maintain. Dry type insulators are better suited for ranges of temperatures that are more moderate such as for example, homes and small businesses, and they require less maintenance
Typical dry type insulators incorporate staple fibers such as aramid or mica. In order to form a matrix of these fibers, varnish is used. The fibers and varnish are blended together to form the matrix which is then formed into the insulator. This creates more processing steps and does not yield ideal mechanical properties because the varnish does not add strength to the fibers. Further, the additional processing steps add to the cost of manufacturing.
While fiber insulation can be manufactured using a simple single press, using such a press to manufacture binder fiber insulation requires additional post-processing to develop enough mechanical stability for use in the mechanical support structure for a power transformer. When utilizing a single press to manufacture dry type insulation, heat and pressure are used to form the insulation. At the end of the process the insulation is removed from the press and it cools. When the insulation cools and is no longer under pressure, it relaxes and loses stability and strength. In essence, the insulation “springs back.” Additional post-processing can be performed to remediate this occurrence but can increase cost and make this a less desirable type of insulation for use in a power transformer or any other suitable application.
Accordingly, it is desirable to provide a processing method for a dry type insulator that can retain its strength and stability even after the processing steps have been completed.